| 摘要 |
1406421 Bulked polyester yarn IMPERIAL CHEMICAL INDUSTRIES LTD 4 Oct 1972 [13 Oct 1971] 9226/71 Heading D1F In a process for producing a bulked synthetic polyester yarn in which yarn in a drawable state is fed by feed rolls via heating means and false twist means to draw rolls which are rotated at a peripheral speed higher than that of the feed rolls by an amount equivalent to the desired draw ratio of the yarn, the yarn in its passage from the false twist means to the draw rolls is made to contact one or more stationary guide surfaces making a total wrap angle of 5‹ to 30‹ therewith. The wrap angle is preferably from 10‹ to 25‹. The linear speed of the yarn at the draw rolls is greater than 70 m/minute. In a preferred embodiment, the yarn is heated in a longitudinally contracted state subsequent to the above process either before or after wind-up. The false twist means may be a false twist spindle or a friction twisting means, and the guide surface in the form of a solid cylindrical pin, preferably ceramic, is positioned within 1 cm of the yarn exit from the false twist means. The presence of the stationary guide surface is said to reduce the number of filament breaks and filament loops within the bulked polyester yarn. Numerical examples are given. |
